The purpose of this study will be to explore the possibility that family members have experienced a very mild form of Kawasaki syndrome. If you/your child agree to participate in this study, a blood sample (2-3 teaspoons) will be obtained to measure non specific inflammatory response (set rate and platelet count and C-reactive protein). When a diagnostic blood test for Kawasaki disease becomes available, the serum from this blood sample (which has been saved by freezing) may be tested.